For the Blueberry Topping:
Preheat Oven 350 degrees F.
Beat eggs with electric mixer.
Add the sugar, salt, milk and vanilla. Beat with electric mixer. Pour into pie shell. Bake until set, about 45 minutes, or until knife inserted about 1 inch from edge comes out clean.
Mix the blueberries, lemon juice, lemon zest and confectioners sugar and spoon over custard before serving.